Optical torque from enhanced scattering by multipolar plasmonic resonance

Yoonkyung E. Lee, Kin Hung Fung, Dafei Jin, Nicholas X. Fang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

10 Citations (Scopus)

Abstract

We present a theoretical study of the optical angular momentum transfer from a circularly polarized plane wave to thin metal nanoparticles of different rotational symmetries. While absorption has been regarded as the predominant mechanism of torque generation on the nanoscale, we demonstrate numerically how the contribution from scattering can be enhanced by using multipolar plasmon resonance. The multipolar modes in non-circular particles can convert the angular momentum carried by the scattered field and thereby produce scattering-dominant optical torque, while a circularly symmetric particle cannot. Our results show that the optical torque induced by resonant scattering can contribute to 80% of the total optical torque in gold particles. This scattering-dominant torque generation is extremely mode-specific, and deserves to be distinguished from the absorption-dominant mechanism. Our findings might have applications in optical manipulation on the nanoscale as well as new designs in plasmonics and metamaterials.
Original languageEnglish
Pages (from-to)343-350
Number of pages8
JournalNanophotonics
Volume3
Issue number6
DOIs
Publication statusPublished - 1 Dec 2014

Keywords

  • light scattering
  • multipolar resonance
  • optical angular momentum
  • optical manipulation
  • optical torque
  • surface plasmon

ASJC Scopus subject areas

  • Biotechnology
  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering

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